Fig 1.
Immunological mechanisms of control of pneumococcal carriage.
The serotype-dependent and -independent immunological mechanisms that control pneumococcal carriage are depicted. Memory B cells and plasma cells specific to capsule and proteins produce IgG. This can lead to antibody-mediated pneumococcal agglutination and antibody-mediated phagocytosis by neutrophils, monocytes, and macrophages. Moreover, IL-17A produced by memory CD4+ T cells might lead to recruitment and activation of neutrophils and monocytes/macrophages, thus increasing phagocytosis. CCL2, C-C motif chemokine ligand 2; CD4+, cluster of differentiation 4; IgG, immunoglobulin G; IL-17A, interleukin 17-A.